CVE-2019-14546 in EspoCRM
Summary
by MITRE
An issue was discovered in EspoCRM before 5.6.9. Stored XSS was executed on the Preference page as well as while sending an email when a malicious payload was inserted inside the Email Signature in the Preference page. The attacker could insert malicious JavaScript inside his email signature, which fires when the victim replies or forwards the mail, thus helping him steal victims' cookies (hence compromising their accounts).
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 11/20/2023
This vulnerability resides in EspoCRM versions prior to 5.6.9 and represents a critical stored cross-site scripting flaw that fundamentally undermines user authentication security. The vulnerability manifests specifically on the Preference page where users can configure their email signatures, creating a persistent attack vector that can compromise user sessions through maliciously crafted JavaScript payloads. The flaw operates by allowing attackers to inject malicious code into the email signature field, which then executes whenever recipients interact with emails containing that signature during reply or forward operations.
The technical implementation of this vulnerability aligns with CWE-79, which catalogs cross-site scripting flaws as a primary concern in web application security. The vulnerability specifically leverages the application's insufficient input validation and output encoding mechanisms when processing email signature data. When users view emails containing malicious signatures, the browser executes the embedded JavaScript code, enabling attackers to perform actions as authenticated users. This particular implementation follows the ATT&CK technique T1531 for credential access through the theft of session cookies and T1566 for initial access via malicious email content.
The operational impact of this vulnerability extends beyond simple data theft, as it provides attackers with persistent access to user accounts through session cookie compromise. The stored nature of the XSS vulnerability means that victims remain compromised until the malicious payload is removed from the preference settings, creating a long-term threat vector. Attackers can leverage this to gain unauthorized access to sensitive customer data, modify records, or escalate privileges within the CRM system. The vulnerability particularly affects organizations relying on EspoCRM for customer relationship management, where the compromise of individual user accounts can lead to broader security breaches.
Mitigation strategies should focus on implementing proper input sanitization and output encoding for all user-controllable data, particularly in email signature fields. Organizations should immediately upgrade to EspoCRM version 5.6.9 or later, which includes patched validation mechanisms. Additionally, implementing content security policies and regular security scanning of user input fields can provide defense-in-depth measures. Network monitoring should be enhanced to detect unusual email processing patterns, and user education regarding suspicious email content should be implemented to reduce successful exploitation attempts. The vulnerability demonstrates the critical importance of validating and sanitizing all user inputs in web applications, particularly those that may be rendered in different contexts such as email communications.